The present invention relates to a method for extracting the contents of a capsule that has a plane of symmetry. The invention also relates to a device for implementing the method.
It is prior art to extract the contents of a closed cartridge. Patent EP 242,556 relates to a device for the preparation of a drink by extracting the contents of a cartridge placed in a cartridge holder for a coffee machine. The drawback with this device is that it comprises a water-injecting member which is a pointed member, and which consequently pierces the cartridge. This piercing of the cartridge is no longer desired, partly because it necessitates the presence of an expensive pointed member, and partly because it causes coffee grounds to move back up the said pointed member.
The object of the present invention is to develop a method and a device in which water can be supplied to extract the contents of a capsule, without tearing the said capsule, in the case of a sealed capsule. The invention also can be used to extract the contents of an open capsule.
The present invention relates to a method for extracting the contents of a capsule that has a plane of symmetry, in which the said capsule is placed in the housing of an extraction system consisting of two clamping elements that enclose between themselves, each for approximately one half, the said housing, in such a way that it is positioned in the system in a plane away from the vertical plane, the said capsule is moved into a vertical plane, in such a way that it is imprisoned leaktightly in the said system, and in such a way that a liquid inlet arrives over the top of the said capsule, and the contents of the said capsule are extracted and the coffee flows out from the bottom of the said capsule.
It is possible in accordance with the invention to extract the contents of both open and sealed capsules. As regards an open capsule, this refers to a plastic capsule or sachets of filter paper and nonwovens. The contents of the capsule are a powdery substance for the preparation of a drink, selected from roasted and ground coffee, tea, instant coffee, a mixture of instant and ground coffees, a hot chocolate product or any other dried substance suitable for consumption.
In the case of sealed capsules, it is possible to extract the contents of the capsule forming the subject-matter of patent application PCT/EP98/03826, namely a sealed flexible sachet in the form of an individual portion designed to be extracted under pressure and containing roasted and ground coffee, the sachet consisting of two identical flexible sheets or a single folded flexible sheet of circular, oval or polygonal form enclosing between the two sheets or between the two faces of the folded sheet a space for the coffee and the two sheets or the two faces of the folded sheet are stuck together around their perimeter in such a way that the said sachet is essentially symmetrical about its joining plane, and the sachet is opened merely by the increase in pressure occasioned by the injection of the extracting fluid, in which the two flexible sheets or the two faces of the folded sheet are extended on one side of the said sachet beyond their join line in order to form between the said sheets or between the two faces of the folded sheet a channel through which the extracting fluid can be introduced, the said channel being approximately perpendicular to the join line to which it leads. The method is not however limited to this kind of capsule and can be used on any capsule with a plane of symmetry and in which the sheets forming the capsule are sealed.
In the method of the invention, the extracting fluid is raised to a pressure sufficient to unseal the two sealed sheets at the point where the said fluid arrives. In practice, the two clamping elements must grip the capsule adequately if the capsule is to resist the increase in pressure during extraction and must provide a good seal around the point where the extracting fluid arrives. The contents of the capsule are normally extracted at a pressure of between 2 and 10 bar, preferably of about 6 to 8 bar on raised and hollow portions situated on at least one of the faces of the clamping elements.
For satisfactory extraction of the coffee from the capsule, a certain amount of time is required for the extraction. However, neither should the extraction take too long, as the consumer wants to keep within the times required for the extraction of conventional espresso coffees. The method according to the invention will normally extract 250 to 300 cm3 per minute.
The advantage of having a method whereby the capsule whose contents are to be extracted is placed in a housing on a plane away from the vertical plane is that in this case the consumer no longer has to hold the capsule holder and engage it in clamping bars. The consumer has merely to place the capsule whose contents are to be extracted in the housing and close the extraction system: this therefore eliminates all risk of disturbance, wrong positioning and the like.
The invention also relates to the device for implementing the method described above. In one embodiment, the device comprises:
an extraction system consisting of two independent and identical clamping elements, enclosing between themselves, each for approximately one half, a housing for the capsule,
clamping means connected to the extraction system and on either side of the said extraction system and allowing the said extraction system to be pivoted from the position away from the vertical plane to the vertical position and closed and opened, and
a lever system connected to the said clamping means mentioned above and enabling the user to work the said means,
the extraction system, the clamping means and the lever system working together on a machine supporting frame and the device also comprising a mobile water inlet system above the system for the extraction of the contents of the capsule between the two clamping elements.
The two clamping elements have seals around the edge of the housing to ensure that the capsule whose contents are to be extracted is gripped firmly. The clamping means must allow a move from the inclined position of the extraction system to the vertical position, while also allowing the two clamping elements to come satisfactorily together, both in order to hold the said capsule properly and to prevent leaks (leaks are especially to be avoided in order that during extraction the seal between each face of the said capsule does not give). The lever allows the user to open and close the extraction system. The result is that the consumer has a very simple task to perform, namely to insert the selected capsule and pull the lever forwards, as explained in greater detail below.
Clearly, when the lever is pulled forwards for extraction, the water inlet must come down at the same time to the top of the extraction system. The water inlet pipe does not need to be fitted with a needle: it is only necessary that the pipe is so positioned that leaks cannot occur, and it is only the pressure of the water that forces its way through the seal of the capsule at the point where the water arrives.
It is possible according to the invention to provide a housing for the capsule of variable size. This means that the capsules for one cup or capsules for two cups can be used, with a mobile water inlet system that adapts itself accordingly.
In the case of a sealed capsule, during extraction, that is when the hot water is entering the capsule, there is a pressure increase inside the said capsule: to produce an opening, there must be raised and hollow portions present in the clamping elements so that a tension sufficient to rupture the material forming the capsule is built up against the said raised and hollow portions. It may be envisaged that one or both of the clamping elements contains raised and hollow portions.
The clamping means that are useable in accordance with the invention may be variously constructed. In one particular embodiment, these clamping means consist of
a clamping rod connected at one end to one of the two clamping elements, halfway along the length of the said element,
an L-shaped clamping lever that is connected at its mid-point to the other end of the clamping rod, is connected to the second clamping element also halfway along the said element and is connected to a master rod, and
a master rod, one end of which slides in a guide at the bottom of the supporting frame on a positioning pin, the other end being connected to the lever system.
In a second embodiment, the device according to the invention comprises:
an extraction system consisting of two independent clamping elements, enclosing between themselves, each for approximately one half, a housing for the capsule, the first clamping element comprising on either side perpendicularly and in the middle of the said element an arm with a translational guide and at the end of the said arm a guide pin and the second element comprising on either side and in the middle of the said element a clamping pin,
clamping means connected to the extraction system and on either side of the said extraction system and allowing the said extraction system to be pivoted from the position away from the vertical plane to the vertical position and closed and opened, and
a lever with two sides extending from the operating bar of the said lever, the latter being connected to the said clamping means mentioned above and enabling the user to work the said means,
the extraction system, the clamping means and the lever working together on a machine supporting frame and the device also comprising a fixed water inlet system above the system for the extraction of the contents of the capsule between the two clamping elements.
As in the first embodiment, the two clamping elements have seals around the edge of the housing to ensure that the capsule whose contents are to be extracted is gripped firmly. The clamping means must allow a move from the inclined position of the extraction system to the vertical position, while also allowing the two clamping elements to come satisfactorily together, both in order to hold the said capsule properly and to prevent leaks (leaks are especially to be avoided in order that during extraction the seal between each face of the said capsule does not give). The lever allows the user to open and close the extraction system. The result is that the consumer has a very simple task to perform, namely to insert the selected capsule and pull the lever forwards, as explained in greater detail below.
When the lever is pulled forwards, at the time of the extraction, the extraction system moves up towards the fixed water inlet system. The consumer places the selected capsule between the two elements of the extraction system and draws the lever forwards, which imparts a translational movement of the first clamping element and then concomitantly an upward movement of both clamping elements towards the fixed water inlet system.
In this embodiment the clamping means are simpler than in the first embodiment. They consist of a master rod, on either side of the lever system and connected at one end to the end of the arm of the said lever and at the other end to a translational and clamping pin of the first clamping element which is situated approximately in the middle of the said first clamping element, the supporting frame of the machine comprising on either side
a translational and clamping guide for the said translational and clamping pin,
a guide for the guide pin of the first clamping element and
a clamping guide for the clamping pin of the second element.
The operation of the device will be explained in greater detail in relation to FIGS. 6 to 9. Each side of the lever forms an elbow with first and second arms, the angle of the elbow is between 100 and 140xc2x0 and the axis of rotation of the said lever is at the intersection of the first and second arms and situated above the supporting frame of the machine. If the device is considered in the closed position, the axis of rotation of the said lever is approximately in the plane of contact between the two clamping elements of the extraction system. The guide for the guide pin of the first clamping element forms an angle of between 0 and 50xc2x0 with the horizontal plane.
The first arm of the lever must be long enough to allow the user to operate the movement of rotation of the said lever without interfering with the rest of the machine, that is with the supporting frame of the said machine. This first arm is normally between 8 and 15 cm long. The second arm of the lever is between 20 and 40 mm long.
The first clamping element has a translational and clamping pin which engages as indicated above with a translational and clamping guide. This guide forms an elbow having an angle of between 100 and 150xc2x0.
As in the first embodiment of the device according to the invention, this second device can be used for open capsules as well as for sealed capsules. In the case of sealed capsules, one or both of the clamping elements comprises raised and hollow portions.